In: Math
Sales of People magazine are compared over a 5-week period at four Borders outlets in Chicago. |
Weekly Sales | |||
Store 1 | Store 2 | Store 3 | Store 4 |
103 | 98 | 89 | 105 |
104 | 77 | 94 | 117 |
105 | 83 | 75 | 86 |
112 | 82 | 104 | 104 |
114 | 98 | 91 | 98 |
Fill in the missing data. (Round your p-value to 4 decimal places, mean values to 1 decimal place, and other answers to 3 decimal places.) |
Treatment | Mean | n | Std. Dev |
Store 1 | |||
Store 2 | |||
Store 3 | |||
Store 4 | |||
Total | |||
One-Factor ANOVA | |||||
Source | SS | df | MS | F | p-value |
Treatment | |||||
Error | |||||
Total | |||||
(a) | Based on the given hypotheses choose the correct option. |
H0: μ1 = μ2 = μ3 = μ4 | |
H1: Not all the means are equal | |
α = 0.05 | |
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|
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(b) | Determine the value of F. (Round your answer to 2 decimal places.) |
F-value |
(c) |
On the basis of the above-determined values, choose the correct decision from below. |
|
(d) | Determine the p-value. (Round your answer to 4 decimal places.) |
p-value |
For the given samples the description of the sample is done in excel tool and some formulas are shown in that as:
Mean =AVERAGE(B2:B6) ,Standard deviation==STDEV.S(B2:B6) | Store 1 | Store 2 | Store 3 | Store 4 | Total |
103 | 98 | 89 | 105 | ||
104 | 77 | 94 | 117 | ||
105 | 83 | 75 | 86 | ||
112 | 82 | 104 | 104 | ||
114 | 98 | 91 | 98 | ||
Mean= | 107.6 | 87.6 | 90.6 | 102 | 387.8 |
n= Sample size= | 5 | 5 | 5 | 5 | 20 |
Standard deviation= | 5.030 | 9.762 | 10.455 | 11.292 |
36.538 |
a) Performing one-factor ANOVA on the given samples in excel results is:
ANOVA: Single Factor | ||||||
SUMMARY | ||||||
Groups | Count | Sum | Average | Variance | ||
Store 1 | 5 | 538 | 107.6 | 25.3 | ||
Store 2 | 5 | 438 | 87.6 | 95.3 | ||
Store 3 | 5 | 453 | 90.6 | 109.3 | ||
Store 4 | 5 | 510 | 102 | 127.5 | ||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Between Groups | 1333.35 | 3 | 444.45 | 4.9743 | 0.0126 | 3.2389 |
Within Groups | 1429.6 | 16 | 89.35 | |||
Total | 2762.95 | 19 |
a) Based on the Hypotheses:
H0: μ1 = μ2 = μ3 = μ4
H1: Not all the means are equal
Rejection region:
At 0.05 level of significance the F-critical value is 3.24 ( As computed in excel or can also be computed using F-table) so, Reject the null hypothesis if F > 3.24.
b) From the One way, ANOVA shown above the F statistic is calculated as:
F=4.97
c) Decision:
On the basis of the above F statistic and calculation, we reject the Null hypothesis since F >F-critical value=3.24.
d) P-value:
The P-value is computed using the excel tool as shown above through ANOVA as:
P-value=0.0126.